Okay, so this is entirely new to me. Sparrow is was an email client for Mac OS X and iOS (and Windows), which brought a decent Gmail experience to these platforms - as opposed to Apple's own not-so-good Gmail support and Google's Gmail iOS application which, well, is just a webpage. Google has now acquired Sparrow, and basically all hell has broken loose, to the point of Rian van der Merwe writing that 'we' lost "faith in a philosophy that we thought was a sustainable way to ensure a healthy future for independent software development, where most innovation happens".

Under the BSD license, the code is freely available and the license requires the original BSD licensee to be properly given credit. The BSD license is, in fact, a free/open license; it is just more closed source friendly.